Android device disconnects after fast roaming due to lost DHCP replies

[shaarkys]

In my case that problem was caused by Routing/NAT offloading on the main router Ubiquiti EdgeRouter X with two APs - Ubiquiti UniFi AC Lite and Ubiquiti UniFi AC Pro - disabling both option on EdgeRouter ensures that Fast Roaming really works without ANY interruptions .

Devices roaming fine but have glitch - 5s after reconnect

Devices roams fine without any glitch...

[himself]

Hey, can you please post your configs? I am getting the same error "kernel: key installation failed" and my Phone disconnects after getting the don't start 4 way handshake message

[Brain2000]

@ahasbini I had this same issue, turned out mine was an issue with the bridges ageing timeout.
If you find it is taking 5 minutes for DHCP to work again for a specific MAC address, check out this thread:

Bridged wifi ap, DHCP Offers only reaching clients after 5 min period

Thank you for posting this, as I spent hours trying to figure out why an external DHCP server could not get packets back to a wifi client. I found the Cisco switch would send DHCP Offer/ACK packets, but they were not passing through the wifi client. I googled that issue specifically, along with the "5 minutes" and came across the bridge ageing information that solved your issue. Lowing the bridge ageing time solved my issue as well. This is only an issue with an external DHCP server when roam…

[chrisliush]

did you figure out your issue?
I have almost same issue now.
if use normal wpa2-psk, it works.
if use fast roam, FT-PSK, initial association is ok, but after getting

don't start 4 way handshake message

no traffic.